1. Field of the Invention
The present invention relates to a wireless battery-powered remote control for remotely controlling the operation of an electric or electronic device. In particular, the invention can be used with a wireless load control system for controlling the amount of power delivered to an electrical load from a source of alternating-current (AC) power, and more particularly, with a remote control for a radio-frequency (RF) lighting control system. Even more particularly, the invention relates to a wireless battery powered remote control having a “glow-in-the-dark” or “night light” feature so that it can be located in the dark.
2. Description of the Related Art
Control systems for controlling the power delivered from an alternating-current (AC) power source to electrical loads, such as lights, motorized window treatments, and fans, are known. Such control systems often use the transmission of radio-frequency (RF) signals to provide wireless communication between the control devices of the system. The prior art lighting control systems include wireless load control devices, such as wall-mounted and table top dimmer switches. The dimmer switches included toggle actuators for turning controlled lighting loads on and off, and intensity adjustment actuators (e.g., rocker switches) for increasing and decreasing the intensities of the lighting loads. The dimmer switches also included one or more visual indicators, e.g., light-emitting diodes (LEDs), for providing feedback of the status of the lighting loads to users of the lighting control system.
The prior art wireless lighting control system also includes wireless remote controls, such as, wall-mounted and table top master controls (e.g., keypads) and car visor controls. The master controls of the prior art lighting control system each include a plurality of buttons and transmit RF signals to the dimmer switches to control the intensities of the controlled lighting loads. The master controls may also each include one or more visual indicators (i.e., LEDs) for providing feedback to the users of the lighting control system. The car visor controls are able to be clipped to the visor of an automobile and include one or more buttons for controlling the lighting loads of the lighting control system. An example of a prior art RF lighting control system is disclosed in commonly-assigned U.S. Pat. No. 5,905,442, issued on May 18, 1999, entitled METHOD AND APPARATUS FOR CONTROLLING AND DETERMINING THE STATUS OF ELECTRICAL DEVICES FROM REMOTE LOCATIONS, the entire disclosure of which is hereby incorporated by reference.
In order to make it easy for the users of the control system to find the control devices in a dark room, the control devices of prior art lighting control systems have often included night light features. For example, some prior art dimmer switches illuminated one or more of the visual indicators to a dim level when the controlled lighting load was off to provide a night light. In addition, some prior art dimmer switches dimly backlit one or more of the actuators when the controlled lighting load was off. However, if the dimmer switch is a “two-wire” device without a connection to the neutral side of the AC power source, the current required to illuminate the night light often needs to be conducted through the lighting load. When the magnitude of the current conducted through the lighting loads is too great, the lighting loads may flicker or provide otherwise poor performance.
Some master controls of the prior art load control system were powered from the AC power source and provided night light features, for example, by dimly illuminating one or more of the visual indicators. However, some of the wireless remote controls of the prior art lighting control systems were powered by batteries, which have limited lifetimes that are dependent upon the usage and the total current drawn from the batteries as well as how often the remote controls are used. The prior art battery-powered remote controls did not provide night lights, and simply illuminated the visual indicators for a period of time after one of the buttons of the remote control was actuated.
Therefore, there is a need for a low-power night light for use in battery-powered remote controls and two-wire load control devices.